1. Field
The following description relates to an apparatus for forming a pattern on a light guide panel that is used for a backlight of a Liquid Crystal Display (LCD), a keypad, a phone, an illuminating surface light source, etc. More particularly, the following description relates to a pattern forming apparatus for forming a light guide pattern by splitting a laser beam into several ones to create a plurality of collected laser beams and scanning the laser beams using a header moving unit movable up/down and left/right, and a light guide panel manufactured using the same.
2. Description of Related Art
In general, a light guide panel is a plate providing a path for uniformly scattering and diffusing light scanned from a light source. The light guide panel is applied to a light receiving flat panel display such as an LCD or a surface light source device for an illuminating signboard, etc.
The surface light source device using the light guide panel is widely using a method of arranging a Cold Cathode Fluorescent Lamp (CCFL) or a Light Emitting Diode (LED) is widely used. This surface light source device is disclosed in Korean Patent Application Nos. 1994-33115, 2001-25870, 2001-53844, 2002-223, 2002-289, 2003-034, 2004-73443, 2005-, 2006-321, 2006-207, etc.
FIG. 1 is a cross section schematically illustrating a surface light source device according to the conventional art.
Referring to FIG. 1, the surface light source device 10 includes a light guide panel 11, a reflection panel 12 installed below the light guide panel 11, a light source 13 installed at a sidewall of the light guide panel 11, and a cover member 14 covering the light source 13.
The light source 13 can be a CCFL, an LED, etc.
A plurality of light guide pattern parts 15 are formed in the light guide panel 11 through printing using titanium oxide (TiO2) having a bead shape and ink including glass, acryl, etc. to scatter and diffuse light incident on one surface of a transparent acryl resin.
In the above-constructed surface light source device 10, light irradiated from the light source 13 is incident on the light guide panel 11, the incident light is guided through the light guide panel 11 as indicated by an arrow, and then the light is reflected by the reflection panel 21 and the light guide pattern part 15 to have a relatively uniform intensity of illumination at each portion.
However, the light guide pattern part 15 formed in a print method has the following drawbacks.
Processes of manufacturing and printing of ink for forming the light guide pattern part 15 are very complicated and a defective ratio of removing or smearing part of a printed portion is very high.
This leads to a low yield of about 80% to 90% of the light guide pattern part 15. Also, because the light guide panel 11 using the print method cannot be reused after a print pattern is removed, the light guide panel 11 cannot be recycled, thus causing pollution. Thus, the light guide panel 11 is not environment-friendly.
Particularly, since the light guide pattern part 15 uses optical reflection of a printed ink object itself, the ink object itself unavoidably absorbs light. This light absorption phenomenon deteriorates the efficiency of light of the surface light source device.
In order to solve the above problems, a non-print method is applied. As the non-print method, there can be an injection molding method using a metal mold.
In the injection molding method, the metal mold 51 has to be repeatedly modified more than dozens of times for pattern optimization. Thus, there is a disadvantage of increasing a cost of development. As a period of time of manufacturing the metal mold 51 increases, it is difficult for a product model to satisfy a suddenly changing demand for development. If a product has a thick thickness, a time of cooling after injection increases to several minutes, thus deteriorating productivity. On the contrary, if a product has a very thin thickness and a wide area, it makes injection imperfect, thus causing a defect such as pattern non-formation.
In order to solve the above problem, there is provided a method for processing a light guide pattern part using a laser. In the case of using the laser, the light guide pattern part can be processed to a desired size without being affected by a deviation of a material thickness and a supplementary device such as a metal mold or a mask is not required. Also, because a light guide pattern is not coated with a separate material, the light guide pattern is recyclable and environment-friendly. However, the method has a disadvantage that a process time increases, so productivity decreases because all patterns have to be molded through a laser process one by one at one time.
Accordingly, embodiments are directed to a light guide panel and an apparatus for forming a pattern on the light guide panel that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.
An object of embodiments is to provide a pattern forming apparatus for a light guide panel, for simultaneously processing a plurality of patterns on the light guide panel.